/*
 * ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is
 *
 * java-concurrency-presentation:
 * concurrency presentation tutorial.
 *
 * The Initial Developer of the Original Code is
 * Marco Antonio Villalobos, Jr.
 * Portions created by the Initial Developer are Copyright (C) 2010
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s): None.
 *
 * ***** END LICENSE BLOCK *****
 */

package presentation.concurrency.util;

import java.util.concurrent.atomic.AtomicLong;

/**
 * Provides a class that does a context switch by forcing a sleep
 * on the current thread.
 */
public class ContextSwitcher {
    final AtomicLong counter = new AtomicLong(0);

    /**
     * Forces a context switch on the current thread.
     */
    public static void force() {
        try {
            Thread.sleep(1);
        } catch (InterruptedException e) {
            //forced a context switch.
        }
    }

    /**
     * Forces a context switch every one thousand calls.
     */
    public void forceSometimes() {
        if (counter.incrementAndGet() % 1000 == 0) {
            try {
                Thread.sleep(1);
            } catch (InterruptedException e) {
                //forced a context switch.
            }
        }
    }
}
